Multiple types of ice making systems have been proposed for automatic ice making machines which continuously produce lumps of ice, and an adequate system is employed according to the usage. One of the systems known is a falling type ice making machine in which an evaporation pipe constituting a refrigeration system is provided at an ice making plate laid out vertically, ice making water is spread over and supplied to the ice making plate which is cooled by a refrigerant circulatively supplied to the evaporation pipe, thereby forming lumps of ice, and separates the obtained lumps of ice and let them fall off (see Japanese Patent Laid-Open Publication No. 2002-62002, for example).
The falling type ice making machine has an ice-making-water tank for retaining a required amount of ice making water under the ice making plate, and is constructed in such a way as to pump out and supply the ice making water in the tank to the ice making plate by a circulation pump at the ice making step, collect the ice making water which has not become ice into the ice-making-water tank, and then feed the ice making water again toward the ice making plate. An ice guide plate is laid out tilted between the ice making plate and the ice-making-water tank, and a stocker is provided on the tilting lower end side of the ice guide plate, so that lumps of ice which fall from the ice making plate are discharged onto the stocker via the ice guide plate. A plurality of through holes are bored in the ice guide plate, so that ice making water falling from the ice making plate is collected into the ice-making-water tank via the through holes without flowing into the stocker. The stocker is provided with ice detection means which detects the storage of lumps of ice up to a predetermined level (detection of fullness), and the operation or stopping of the ice making machine is controlled by a detection signal from the ice detection means.